I doubt the white and red mystery Merckx frame is a Corsa model, judging by the brake bridge and I am pretty sure paint isn't original either. I would say it is either a Strada or a Corsa Extra, judging by the looks of it. If the dropouts are stamped Brev Campagnolo, then you have a Corsa Extra. Otherwise it is probably a Strada model. The way the seat stays are attached to the seat tube is not uncommon, although you don't see this very often. I found a couple of references in my archives on different model. You can check them out here:
@SWijland thanks for helping
As is possible see in this photo, the dropouts are stamped Brev Campagnolo so it's a Corsa Extra? The top of seat stays is like the Corsa-01 without stamping.
I doubt the white and red mystery Merckx frame is a Corsa model, judging by the brake bridge and I am pretty sure paint isn't original either. I would say it is either a Strada or a Corsa Extra, judging by the looks of it. If the dropouts are stamped Brev Campagnolo, then you have a Corsa Extra. Otherwise it is probably a Strada model. The way the seat stays are attached to the seat tube is not uncommon, although you don't see this very often. I found a couple of references in my archives on different model. You can check them out here:
Strada
Corsa-01
Team Hitachi
Corsa Extra